When the Grand National comes around, trends and stats are used more than ever to analyse the big race (often viewed as an impossible puzzle). Rather than taking these at face value (eg, 8 of the last 10 winners were aged between 9 and 11), it’s worth taking a closer look at them:
10-Year Age Stats
The grid above shows that all of the last 10 winners were aged between 8 and 11, as were 38 of the total 40 horses to which finished in the top 4. However, so were 84% of the total field. This suggests that this group of horses over-performed, if not by a huge amount. There was a significant underperformance from horses aged 7 or younger, despite this sample being relatively small. The slight underperformance from 10yo’s may suggest that we should focus on 8- and 9-year-olds, but the significant over-performance of 11yo’s would suggest otherwise.
The changes to the race in recent years are well documented, and it may be worth looking at the last 5 renewals to find out whether the trends are changing.
5-Year Age Stats
3 of the last 5 winners were aged 8 or 9 – however, the other 2 were aged 11. Again, we see an underperformance from 10yo’s, but there is also an underperformance from the 9yo’s in the last 5 renewals. Some might argue that this shows a shift towards younger horses, but the 9% over-performance from 11yo’s (including 2 wins) suggests that this would be a knee-jerk reaction.
Horses aged younger than 8 or older than 11 have struggled to win the race – although not a huge amount of them have run and it’s difficult to simply discard such runners on this basis.
Of the others, the best record has been that of 11yo’s, with 8yo’s also performing well. However, any useful trends should be backed up by logic and it’s hard to make a case for 11- and 8-year-olds performing well when 9- and 10-year-olds don’t.